Enhanced mobility mattress

ABSTRACT

A mattress includes a first layer of viscoelastic foam having an upper surface and a layer of non-viscoelastic foam supporting the first layer. The mattress also includes a plurality of static bolster elements positioned beneath the upper surface and clustered together to define a plurality of troughs between adjacent bolster elements. The first layer of viscoelastic foam is further compressible in regions of the mattress corresponding with the troughs than surrounding regions corresponding with the bolster elements. Each of the bolster elements is capable of exerting a reaction force having a lateral component on an individual pushing against the bolster element with a line of action through one of the troughs.

FIELD OF THE INVENTION

The present invention relates to mattresses, and more particularly to mattresses including one or more layers of foam.

BACKGROUND OF THE INVENTION

Conventional mattresses can be found in a wide variety of shapes and sizes. Many mattresses are constructed entirely or partially out of foam material. For example, polyurethane foam is commonly used in many mattresses, pillows, and cushions, and can be used alone or in combination with other types of cushion materials. In many mattresses, viscoelastic material is used, providing the mattress with an increased ability to conform to a user and to distribute the weight or other load of the user. Although the shape-conforming property of viscoelastic foam is desirable for use in mattresses, it can also impair the user's mobility while supported on the mattress. For example, the user may have difficulty exerting force on the mattress in order to change positions. In some cases, this impaired mobility is due at least in part to the design of the mattress and/or the choice of materials) used in various locations of the mattress.

Based at least in part upon the limitations of existing mattresses and the high consumer demand for improved mattresses in a wide variety of applications, new mattresses are welcome additions to the art.

SUMMARY OF THE INVENTION ION

The invention provides, in one aspect, a mattress including a first layer of viscoelastic foam having an upper surface and a layer of non-viscoelastic foam supporting the first layer. The mattress also includes a plurality of static bolster elements positioned beneath the upper surface and clustered together to define a plurality of troughs between adjacent bolster elements. The first layer of viscoelastic foam is further compressible in regions of the mattress corresponding with the troughs than surrounding regions corresponding with the bolster elements. Each of the bolster elements is capable of exerting a reaction force having a lateral component on an individual pushing against the bolster element with a line of action through one of the troughs.

The invention provides, in another aspect, a mattress including a first layer of viscoelastic foam having an upper surface and a layer of non-viscoelastic foam supporting the first layer. The mattress also includes a plurality of static bolster elements positioned beneath the upper surface and clustered together to define a plurality of troughs between adjacent bolster elements. The bolster elements and the troughs extend in a direction parallel to a length of the mattress, and the bolster elements include a hardness that is at least about 2,5 times a hardness of the first layer of viscoelastic foam.

Other features and aspects of the invention will become apparent by consideration of the following detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a mattress according a first embodiment of the invention.

FIG. 2 is a cross-sectional view of the mattress of FIG. 1, taken along line 2-2 of FIG. 1.

FIG. 3 is a perspective view of a mattress according a second embodiment of the invention.

FIG. 4 is a cross-sectional view of the mattress of FIG. 3, taken along line 4-4 of FIG. 3.

FIG. 5 is a perspective view of a mattress according a third embodiment of the invention.

FIG. 6 is a cross-sectional view of the mattress of FIG. 5, taken along line 6-6 of FIG. 5.

FIG. 7 is a perspective view of a mattress according a fourth embodiment of the invention.

FIG. 8 is a cross-sectional view of the mattress of FIG. 7, taken along line 8-8 of FIG. 7.

FIG. 9 is a perspective view of a mattress according a fifth embodiment the invention.

FIG. 10 is a cross-sectional view of the mattress of FIG. 9, taken along line 10-10 of FIG. 9.

FIG. 11 is a perspective view of a mattress according a sixth embodiment of the invention.

FIG. 12 is a cross-sectional view of the mattress of FIG. 11, taken along line 12-12 of FIG. 11.

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the accompanying drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

DETAILED DESCRIPTION

FIG. 1 illustrates a mattress 110 according to an embodiment of the invention. The mattress 110 includes a top, surface 114, a bottom surface 118, and a thickness t (FIG. 2) between the top surface 114 and the bottom surface 118. The mattress 110 is substantially rectangular in shape and includes a length dimension L and a width dimension W (FIG. 1). In other embodiments, the mattress 110 may include any of a number of different shapes.

In the illustrated embodiment of the mattress 110 as shown in FIGS. 1 and 2, the top surface 114 and the bottom surface 118 are substantially planar. Alternatively, either or both of the top and bottom surfaces 114, 118 may be non-planar, including without limitation surfaces having ribs, bumps, waves, and other protrusions of any shape and size, surfaces having grooves and other apertures, and the like.

With reference to FIG. 2, the mattress 110 includes a plurality of foam layers that interact to provide the mattress 110 with a soft and comfortable feel, while providing adequate support for the user. In the illustrated embodiment, the mattress 110 includes a first or overlying viscoelastic foam layer 122 and a second or underlying non-viscoelastic foam layer 126, which may include latex, standard polyurethane foam, high-resilience polyurethane foam, or any expanded polymer (e.g., expanded ethylene vinyl acetate, polypropylene, polystyrene, or polyethylene). The viscoelastic foam layer 122 provides, the body-conforming and low-resilience qualities associated with viscoelastic foam, while the non-viscoelastic foam layer enhances and/or provides some degree of resilience or “bounce” to the mattress 110 typically associated with conventional spring-based mattresses.

With continued reference to FIG. 2, the viscoelastic foam layer 122 includes a top surface 122 a and a bottom surface 122 b. In the illustrated embodiment, the top surface 122 a coincides with the top surface 114 of the mattress 110. In other embodiments, a pad, topper or one or more other foam or non-foam layers may be positioned upon the top surface 122 a. In the illustrated embodiment of FIG. 1, both the top surface 122 a and the bottom surface 122 b are substantially planar. In other embodiments, at least one of the top surface 122 a and the bottom surface 122 b may be non-planar, including without limitation surfaces having ribs, bumps, waves, and other protrusions of any shape and size, surfaces having grooves and other apertures that extend partially or fully through the viscoelastic foam layer 122, and the like.

In some embodiments, the viscoelastic foam layer 122 has a hardness of at least about 20 N and no greater than about 80 N for desirable softness and body-conforming qualities. In other embodiments, the viscoelastic foam layer 122 may have a hardness of at least about 30 N and no greater than about 70 N. In still other embodiments, the viscoelastic foam layer 122 may have a hardness of at least about 40 N and no greater than about 60 N. Unless otherwise specified, the hardness of any foam material referred to herein is measured by exerting pressure from a plate against a sample of the material to a compression of 40% of an original thickness of the material at approximately room temperature (e.g., 21-23 Degrees Celsius), wherein the 40% compression is held for a set period of time, following the International Organization of Standardization (ISO) 2439 hardness measuring standard.

The viscoelastic foam layer 122 also includes a density providing a relatively high degree of material durability. The density of the viscoelastic foam layer 122 can also impact other characteristics of the foam, such as the manner in which the viscoelastic foam layer 122 responds to pressure, and the feel of the foam. In some embodiments, the viscoelastic foam layer 122 has a density of no less than about 30 kg/m³ and no greater than about 150 kg/m³. In other embodiments, the viscoelastic foam layer 122 may have a density of at least about 40 kg/m³ and no greater than about 135 kg/m³. In still other embodiments, the viscoelastic foam layer 122 may have a density of at least about 50 kg/m³ and no greater than about 120 kg/m³.

With reference to FIGS. 1 and 2, the viscoelastic foam layer 122 of the mattress 110 includes a cellular structure in which the walls of the individual cells are substantially intact (i.e. non-reticulated viscoelastic foam). In other embodiments, the viscoelastic foam layer 122 may be reticulated. Reticulated viscoelastic foam has characteristics that are well suited for use in the mattress 110, including an enhanced ability (i.e., when compared to non-reticulated viscoelastic foam) to permit the movement of air therethrough, thereby providing enhanced air and/or heat movement within, through, and away from the viscoelastic foam layer 122. Reticulated foam is a cellular foam structure in which the cells of the foam are essentially skeletal. In other words, the cells of the reticulated foam are each defined by a plurality of apertured windows surrounded by cell struts. The cell windows of reticulated foam can be entirely gone (leaving only the cell struts) or substantially gone. In some embodiments, the foam is considered “reticulated” if at least 50% of the windows of the cells are missing (i.e., windows having apertures therethrough, or windows that are completely missing and therefore leaving only the cell struts). Such structures can be created by destruction or other removal of cell window material, or preventing the complete formation of cell windows during the manufacturing process of the foam.

With continued reference to FIGS. 1 and 2, the second or non-viscoelastic foam layer 126 includes a top surface 126 a and a bottom surface 126 b. The top surface 126 a is positioned adjacent the bottom surface 122 b of the viscoelastic foam layer 122, such that the non-viscoelastic foam layer 126 supports the viscoelastic foam layer 122. In some embodiments, the viscoelastic foam layer 122 can rest upon the non-viscoelastic foam layer 126 without being secured thereto. However, in other embodiments, the layers 122, 126 may be secured to one another by adhesive or cohesive bonding material, and/or by being bonded together during formation of the layers 122, 126. Tape, a hook and loop fastener material, conventional fasteners, stitches extending at least partially through the layers 122, 126, or any of a number of different structures or processes may be utilized to secure the layers 122, 126 to each other. For example, thin adhesive strips (not shown) may be positioned between the layers 122, 126. Such adhesives may extend across the entire width and length of the mattress 110, or in some embodiments may instead extend only across discrete portions of the width and/or length of the mattress 110. Such adhesive strips are flexible enough to form a softer structure than other, more conventional adhesive glues.

In the illustrated embodiment of the mattress 110 as shown in FIGS. 1 and 2, both the top surface 126 a and the bottom surface 126 b of the non-viscoelastic foam layer 126 are substantially planar. In other embodiments, at least one of the top surface 126 a and the bottom surface 126 b may be non-planar, including without limitation surfaces having ribs, bumps, waves, and other protrusions of any shape and size, surfaces having grooves, and other apertures that extend partially or fully through the non-viscoelastic foam layer 126, and the like.

In some embodiments of the mattress 110, the non-viscoelastic foam layer 126 includes latex foam having a hardness of at least about 30 N and no greater than about 130 N for a desirable overall mattress firmness and “bounce” when used in conjunction with the viscoelastic foam layer 122 described above. In other embodiments, the non-viscoelastic foam layer 126 includes high-resilience polyurethane foam having a hardness of at least about 80 N and no greater than about 200 N. In still other embodiments, the non-viscoelastic foam layer 126 has hardness of at least about 40 N and no greater than about 120 N for this purpose. In other embodiments, the non-viscoelastic foam layer 126 may have a hardness of at least about 50 N and no greater than about 110 N.

In some embodiments, the non-viscoelastic foam layer 126 includes latex foam having a density of no less than about 40 kg/m³ and no greater than about 100 kg/m³. In other embodiments, the non-viscoelastic foam layer 126 includes high-resilience polyurethane foam having a density of no less than about 10 kg/m³ and no greater than about 80 kg/m³. In still other embodiments, the non-viscoelastic foam layer 126 may have a density of at least about 50 kg/m³ and no greater than about 100 kg/m³. In other embodiments, the non-viscoelastic foam layer 126 may have a density of at least about 60 kg/m³ and no greater than about 100 kg/m³.

With continued reference to FIGS. 1 and 2, the mattress 110 includes a plurality of bolster elements 130 positioned beneath the top surface 122 a of the viscoelastic foam layer 122. In the illustrated embodiment, the bolster elements 130 extend along the entire length L of the mattress 110 and are positioned within the non-viscoelastic foam layer 126. More particularly, the bolster elements 130 are disposed between the top surface 126 a and the bottom surface 126 b such that the bolster elements 130 are substantially encased by the non-viscoelastic foam layer 126. However, the bolster elements 130 are not limited to being encased by the non-viscoelastic foam layer 126, and may extend through the mattress 110 at any point along the thickness t, between the top surface 126 a of the viscoelastic foam layer 122 and the bottom surface 126 b of the non-viscoelastic foam layer 126. In addition, the bolster elements 130 may be shorter than the length L of the mattress 110.

In the illustrated embodiment of the mattress 110, the bolster elements 130 have a generally hexagonal cross-sectional shape, and each of the plurality of bolster elements 130 is substantially identical. Adjacent bolster elements 130 are positioned contiguously such that adjacent bolster elements 130 are in contact with each other. In other embodiments, adjacent bolster elements 130 may be spaced apart or may overlap. Furthermore, bolster elements 130 having other cross-sectional shapes may be utilized in the mattress 110.

The bolster elements 130 are formed from a suitable high-resilience polymeric material, such as polystyrene foam. In some embodiments, the bolster elements 130 can include any expanded polymer (e.g., expanded ethylene vinyl acetate, polypropylene, polyethylene, and the like). The bolster elements 130 may be formed individually by any suitable process (e,g., by direct injection expanded foam molding). In other embodiments, the bolster elements 130 may be formed together as a single piece. The bolster elements 130 may be formed separately from the non-viscoelastic foam layer 126 and subsequently positioned within the layer 126 (e.g., within cavities formed or otherwise created in the layer 126), or the bolster elements 130 may be formed simultaneously with the non-viscoelastic foam layer 126 using a co-injection molding process. In the illustrated embodiment of the mattress 110, the bolster elements 130 have a hardness of at least about 200 N. In some embodiments, the bolster elements 130 may have a hardness of at least about 2.5 times the hardness of the viscoelastic foam layer 122 and no greater than about 10 times the hardness of the viscoelastic foam layer 122. In such embodiments, the bolster elements can also have a hardness that is greater than that of the non-viscoelastic foam layer 126, such as a hardness of at least 1.1 times that of the non-viscoelastic foam layer 126, or (in other embodiments) a hardness of at least 1.5 times that of the non-viscoelastic foam layer 126, or (in still other embodiments) a hardness that is at least twice that of the non-viscoelastic foam layer 126.

With reference to FIG. 2, a plurality of troughs 134 is defined between adjacent bolster elements 130. Each of the troughs 134 is defined by facing, oblique surfaces 138 of adjacent bolster elements 130, respectively. In the illustrated embodiment of the mattress 110, the troughs 134 extend along the entire length L of the mattress 110 with the bolster elements 130. Under an applied force (e.g., in response to a user's weight or exertion), the viscoelastic foam layer 122 may be deformed or compressed further into regions 136 of the mattress 110 corresponding with the troughs 134 than regions 132 of the mattress 110 surrounding the troughs 134 as a result of the relatively high hardness of the bolster elements 130 compared to the layers 122, 126. Accordingly, the user is able to feel the locations of the bolster elements 130 by compressing the foam layers 122, 126 into the troughs 134.

The troughs 134 provide the user with locations or regions 136 on the mattress 110 where the user may increase their mobility (i.e., leverage to initiate movement) on the mattress 110. For example, as shown in FIG. 2, when the user desires to move or change position, the user exerts a force F on the mattress 110 having a line of action through one of the troughs 134. A corresponding reaction force R is exerted on the user by the bolster elements 130. Depending upon the particular line of action of the exertion force F, the reaction force R may have a line of action normal to the surface 138 of the bolster element 130. The reaction force R may be resolved into at least horizontal and vertical force vector components Rx, Ry. The horizontal component is hereafter referred to as a lateral component.

The lateral component Rx of the reaction force R exerted on the user by one or more of the bolster elements 130 allows the user to accelerate a mass (e.g., the user's body) in a lateral direction. This facilitates lateral movement of the user on the mattress 110, and enables the user to roll, turn, or move off the mattress 110 with reduced effort. In some conventional mattresses including viscoelastic foam, the shape-conforming properties of the viscoelastic foam might allow the user to “sink” into the foam and thereby inhibit their lateral movement, causing the user to struggle when rolling, turning, or moving off such a conventional mattress.

FIGS. 3 and 4 illustrate a mattress 210 according to another embodiment of the invention. This embodiment employs much of the same structure and has many of the same properties as the embodiment of the mattress 110 described above in connection with FIGS. 1 and 2. Accordingly, the following description focuses primarily upon the structure and features that are different than the embodiment described above in connection with FIGS. 1 and 2. Reference should be made to the description above in connection with FIGS. 1 and 2 for additional information regarding the structure and features, and possible alternatives to the structure and features of the mattress illustrated in FIGS. 3 and 4 and described below. Structure and features of the embodiment shown in FIGS. 3 and 4 that correspond to structure and features of the embodiment of FIGS. 1 and 2 are designated hereinafter in the 200 series of reference numbers.

With reference to FIG. 3, the mattress 210 includes a top surface 214, a bottom surface 218, and a thickness t (FIG. 4) between the top surface 214 and the bottom surface 218. The mattress 210 is substantially rectangular in shape and includes a length dimension L and a width dimension W (FIG. 3). In the illustrated embodiment of the mattress 210 as shown in FIGS. 3 and 4, the top surface 214 and the bottom surface 218 are substantially planar.

The mattress 210 includes a first or overlying viscoelastic foam layer 222 and a second or underlying non-viscoelastic foam layer 226. The viscoelastic foam layer 222 provides the body-conforming and low-resilience qualities associated with viscoelastic foam, while the non-viscoelastic, foam layer enhances and/or provides some degree of resilience or “bounce” to the mattress 210 typically associated with conventional spring-based mattresses.

Like the mattress 110 described above, the mattress 210 includes a plurality of bolster elements 230 positioned beneath a top surface 222 a of the viscoelastic foam layer 222. In the illustrated embodiment, the bolster elements 230 extend along the entire length L of the mattress 210 and are positioned within the non-viscoelastic foam layer 226. More particularly, the bolster elements 230 are disposed between a top surface 226 a and a bottom surface 226 b of the non-viscoelastic foam layer 226 such that the bolster elements 230 are substantially encased by the non-viscoelastic foam layer 226. However, the bolster elements 230 are not limited to being encased by the non-viscoelastic foam layer 226, and may extend through the mattress 210 at any point along the thickness t, between the top surface 226 a of the viscoelastic foam layer 222 and the bottom surface 226 b of the non-viscoelastic foam layer 226. In addition, the bolster elements 230 may be shorter than the length L of the mattress 210.

In the illustrated embodiment of the mattress 210, the bolster elements 230 have a generally circular cross-sectional shape, and each of the plurality of bolster elements 230 is substantially identical. Adjacent bolster elements 230 are positioned contiguously such that adjacent bolster elements 230 are in contact with each other. In other embodiments, adjacent bolster elements 230 may be spaced apart or may overlap. Furthermore, bolster elements 230 having other cross-sectional shapes may be utilized in the mattress 210.

Like the bolster elements 130 described above, the bolster elements 230 are formed from a suitable high-resilience polymeric material, such as polystyrene foam. In some embodiments, the bolster elements 230 can include any expanded polymer (e.g., expanded ethylene vinyl acetate, polypropylene, polyethylene, and the like). The bolster elements 230 may be formed individually by any suitable process (e.g., by direct injection expanded foam molding). In other embodiments, the bolster elements 230 may be formed together as a single piece. The bolster elements 230 may be formed separately from the non-viscoelastic foam layer 226 and subsequently positioned within the layer 226 (e.g., within cavities formed or otherwise created in the layer 226), or the bolster elements 230 may be formed simultaneously with the non-viscoelastic foam layer 226 using a co-injection molding process. In the illustrated embodiment of the mattress 210, the bolster elements 230 have a hardness of at least about 200 N. In some embodiments, the bolster elements 230 may have a hardness of at least about 2.5 times the hardness of the viscoelastic foam layer 222 and no greater than about 10 times the hardness of the viscoelastic foam layer 222. In such embodiments, the bolster elements can also have a hardness that is greater than that of the non-viscoelastic foam layer 226, such as a hardness of at least 1.1 times that of the non-viscoelastic foam layer 226, or (in other embodiments) a hardness of at least 1.5 times that of the non-viscoelastic foam layer 226, or (in still other embodiments) a hardness that is at least twice that of the non-viscoelastic foam layer 226.

With reference to FIG. 4, a plurality of troughs 234 is defined between adjacent bolster elements 230. Each of the troughs 234 is defined by facing, arcuate surfaces 238 of adjacent bolster elements 230, respectively. In the illustrated embodiment of the mattress 210, the troughs 234 extend along the entire length L of the mattress 210 with the bolster elements 230. Under an applied force (e.g., in response to a user's weight or exertion), the viscoelastic foam layer 222 may be deformed or compressed further into regions 236 of the mattress 210 corresponding with the troughs 234 than regions 232 of the mattress 210 surrounding the troughs 234 as a result of the relatively high hardness of the bolster elements 230 compared to the layers 222, 226. Accordingly, the user is able to feel the locations of the bolster elements 230 by compressing the foam layers 222, 226 into the troughs 234.

The troughs 234 provide the user with locations or regions 236 on the mattress 210 where the user may increase their mobility (i.e., leverage to initiate movement) on the mattress 210. For example, as shown in FIG. 4, when the user desires to move or change position, the user exerts a force F on the mattress 210 having a line of action through one of the troughs 234. A corresponding reaction force R is exerted on the user by the bolster elements 230. Depending upon the particular line of action of the exertion force F, the reaction force R may have a line of action normal to the surface 238 of the bolster element 230. The reaction force R may be resolved into at least lateral and vertical force vector components Rx, Ry.

The lateral component Rx of the reaction force R exerted on the user by one or more of the bolster elements 230 allows the user to accelerate a mass (e.g., the user's body) in a lateral direction. This facilitates lateral movement of the user on the mattress 210, and enables the user to roll, turn, or move off the mattress 210 with reduced effort. In some conventional mattresses including viscoelastic foam, the shape-conforming properties of the viscoelastic foam might allow the user to “sink” into the foam and thereby inhibit their lateral movement, causing the user to struggle when rolling, turning, or moving off such a conventional mattress.

FIGS. 5 and 6 illustrate a mattress 310 according to another embodiment the invention. This embodiment employs much of the same structure and has many of the same properties as the embodiments of the mattresses 110 and 210 described above in connection with FIGS. 1-4. Accordingly, the following description focuses primarily upon the structure and features that are different than the embodiments described above in connection with FIGS. 1-4. Reference should be made to the description above in connection with FIGS. 1-4 for additional information regarding the structure and features, and possible alternatives to the structure and features of the mattress 310 illustrated in FIGS. 5 and 6 and described below. Structure and features of the embodiment shown in FIGS. 5 and 6 that correspond to structure and features of the embodiment of FIGS. 1-4 are designated hereinafter in the 300 series of reference numbers.

With reference to FIG. 5, the mattress 310 includes a top surface 314, a bottom surface 318, and a thickness t (FIG. 6) between the top surface 314 and the bottom surface 318. The mattress 310 is substantially rectangular in shape and includes a length dimension L and a width dimension W (FIG. 1). In the illustrated embodiment of the mattress 310 as shown in FIGS. 5 and 6, the top surface 314 and the bottom surface 318 are substantially planar.

The mattress 310 includes a first or overlying viscoelastic foam layer 322 and a second or underlying non-viscoelastic foam layer 326. The viscoelastic foam layer 322 provides the body-conforming and low-resilience benefits associated with viscoelastic foam, while the non-viscoelastic foam layer 326 enhances and/or provides some degree of resilience or “bounce” to the mattress 310 typically associated with conventional spring-based mattresses.

Like the mattresses 110 and 210 described above, the mattress 310 includes a plurality of bolster elements 330 positioned beneath a top surface 322 a of the viscoelastic foam layer 322. In the illustrated embodiment, the bolster elements 330 extend along the entire length L of the mattress 310 and are positioned within the non-viscoelastic foam layer 326. More particularly, the bolster elements 330 are disposed between a top surface 326 a and a bottom surface 326 b of the non-viscoelastic foam layer 326 such that the bolster elements 330 are substantially encased by the non-viscoelastic foam layer 326. However, the bolster elements 330 are not limited to being encased by the non-viscoelastic foam layer 326, and may extend through the mattress 310 at any point along the thickness t, between the top surface 326 a of the viscoelastic foam layer 322 and the bottom surface 326 b of the non-viscoelastic foam layer 326. In addition, the bolster elements 330 may be shorter than the length L of the mattress 310.

With reference to FIG. 6, the bolster elements 330 have a generally hexagonal cross-sectional shape, and each of the plurality of bolster elements 330 is substantially identical. Additionally, the bolster elements 330 are arranged, in a first row 340 and a second row 344 substantially identical to the first row 340. Horizontally adjacent bolster elements 330 in both the first row 340 and the second row 344 are positioned contiguously such that adjacent bolster elements 330 are in contact with each other. The first row 340 is also positioned contiguously with the second row 344 such that vertically adjacent bolster elements 330 are substantially aligned and in contact with each other. In other embodiments, adjacent bolster elements 330 may be spaced apart or may overlap. Furthermore bolster elements 330 having other cross-sectional shapes may be utilized, any number of rows of bolster elements 330 may be used, and vertically adjacent rows of bolster elements 330 may be positioned relative to one another in any suitable manner (e.g., spaced apart, nested, etc.).

Like the bolster elements 130 and 230 described above, the bolster elements 330 are formed from a suitable high-resilience polymeric material, such as polystyrene foam. In some embodiments, the bolster elements 330 can include any expanded polymer (e.g., expanded ethylene vinyl acetate, polypropylene, polyethylene, and the like). The bolster elements 330 may be formed individually by any suitable process (e.g., by direct injection expanded foam molding). In other embodiments, the bolster elements 330 may be formed together as a single piece. The bolster elements 330 may be formed separately from the non-viscoelastic foam layer 326 and subsequently positioned within the layer 326 (e.g., within cavities formed or otherwise created in the layer 326), or the bolster elements 330 may be formed simultaneously with the non-viscoelastic foam layer 326 using a co-injection molding process. In the illustrated embodiment of the mattress 310, the bolster elements 330 have a hardness of at least about 200 N. In some embodiments, the bolster elements 330 may have a hardness of at least about 2.5 times the hardness of the viscoelastic foam layer 322 and no greater than about 10 times the hardness of the viscoelastic foam layer 322. In such embodiments, the bolster elements can also have a hardness that is greater than that of the non-viscoelastic foam layer 326, such as a hardness of at least 1.1 times that of the non-viscoelastic foam layer 326, or (in other embodiments) a hardness of at least 1.5 times that of the non-viscoelastic foam layer 326, or (in still other embodiments) a hardness that is at least twice that of the non-viscoelastic foam layer 326.

With reference to FIG. 6, a plurality of troughs 334 is defined between adjacent bolster elements 330 in the first row 340. Each of the troughs 334 is defined by facing, oblique surfaces 338 of adjacent bolster elements 330, respectively. In the illustrated embodiment of the mattress 310, the troughs 334 extend along the entire length L of the mattress 310 with the bolster elements 330. Under an applied force (e.g., in response to a user's weight or exertion), the viscoelastic foam layer 322 may be deformed or compressed further into regions 336 of the mattress 310 corresponding with the troughs 334 than regions 332 of the mattress 310 surrounding the troughs 334 as a result of the relatively high hardness of the bolster elements 330 compared to the layers 322, 326. Accordingly, the user is able to feel the locations of the bolster elements 330 by compressing the foam layers 322, 326 into the troughs 334.

The troughs 334 provide the user with locations or regions 336 on the mattress 310 where the user may increase their mobility (i.e., leverage to initiate movement) on the mattress 310. For example, as shown in FIG. 6, when the user desires to move or change position, the user exerts a force F on the mattress 310 having a line of action through one of the troughs 334. A corresponding reaction force R is exerted on the user by the bolster elements 330. Depending upon the particular line of action of the exertion force F, the reaction force R may have a line of action normal to the surface 338 of the bolster element 330. The reaction force R may be resolved into at least lateral and vertical force vector components Rx, Ry.

The lateral component Rx of the reaction force R exerted on the user by one or more of the bolster elements 330 allows the user to accelerate a mass (e.g., the user's body) in a lateral direction. This facilitates lateral movement of the user on the mattress 310, and enables the user to roll, turn, or move off the mattress 310 with reduced effort. In some conventional mattresses including viscoelastic foam, the shape-conforming properties of the viscoelastic foam might allow the user to “sink” into the foam and thereby inhibit their lateral movement, causing the user to struggle when rolling, turning, or moving off such a conventional mattress.

FIGS. 7 and 8 illustrate a mattress 410 according to another embodiment of the invention. This embodiment employs much of the same structure and has many of the same properties as the embodiments of the mattresses 110-310 described above in connection with FIGS. 1-6. Accordingly, the following description focuses primarily upon the structure and features that are different than the embodiments described above in connection with FIGS. 1-6. Reference should be made to the description above in connection with FIGS. 1-6 for additional information regarding the structure and features, and possible alternatives to the structure and features of the mattress 410 illustrated in FIGS. 7 and 8 and described below. Structure and features of the embodiment shown in FIGS. 7 and 8 that correspond to structure and features of the embodiment of FIGS. 1-6 are designated hereinafter in the 400 series of reference numbers.

With reference to FIG. 7, the mattress 410 includes a top surface 414, a bottom surface 418, and a thickness t (FIG. 8) between the top surface 414 and the bottom surface 418. The mattress 410 is substantially rectangular in shape and includes a length dimension L and a width dimension W (FIG. 7). In the illustrated embodiment of the mattress 410 as shown in FIGS. 7 and 8, the top surface 414 and the bottom surface 418 are substantially planar.

The mattress 410 includes a first or overlying viscoelastic foam layer 422 and a second or underlying non-viscoelastic foam layer 426. The viscoelastic foam layer 422 provides the body-conforming and low-resilience qualities associated with viscoelastic foam, while the non-viscoelastic foam layer enhances and/or provides some degree of resilience or “bounce” to the mattress 410 typically associated with conventional spring-based mattresses.

The mattress 410 includes a plurality of bolster elements 430 positioned beneath a top surface 422 a of the viscoelastic foam layer 422. The bolster elements 430 have a generally circular cross-sectional shape and are elongated in a thickness direction of the mattress 430. In other words, the bolster elements 430 are cylindrical and extend along the thickness dimension of the mattress 410. Accordingly, the bolster elements 430 are comparatively shorter in length and more numerous than any of the bolster elements 130, 230, or 330 described above.

In the illustrated embodiment, the bolster elements 430 are disposed between a top surface 426 a and a bottom surface 426 b of the non-viscoelastic foam layer 426 such that the bolster elements 430 are substantially encased by the non-viscoelastic foam layer 426. However, the bolster elements 430 are not limited to being encased by the non-viscoelastic foam layer 426.

Adjacent bolster elements 430 are positioned contiguously, such that the bolster elements 430 form an array of rows extending along the width W of the mattress 410 and columns extending along the length L of the mattress 410 (FIG. 7). Each row of bolster elements 430 is substantially identical (i.e., each row of bolster elements 430 has the same quantity and arrangement of bolster elements 430), and each column of bolster elements 430 is substantially identical (i.e., each column of bolster elements 430 has the same quantity and arrangement of bolster elements 430). Furthermore, the individual bolster elements 430 are substantially identical. In other embodiments, adjacent bolster elements 430 may be spaced apart or may overlap, or bolster elements 430 having other cross-sectional shapes may be utilized. In addition, any number of rows or columns of bolster elements 430 may be used, and bolster elements 430 may be positioned relative to one another in any suitable manner (e.g., spaced apart, nested, etc.).

With reference to FIG. 8, the bolster elements 430 include flat surfaces 448 that are coplanar with each other, such that an aggregate of the flat surfaces 448 defines a single plane substantially parallel to the top surface 422 a. The contiguous arrangement of the bolster elements 430 defines a plurality of troughs 434 between adjacent rows and columns of bolster elements 430.

Like the bolster elements 130, 230, and 330 described above, the bolster elements 430 are formed from a suitable high-resilience polymeric material, such as polystyrene foam. In some embodiments, the bolster elements 430 can include any expanded polymer (e.g., expanded ethylene vinyl acetate, polypropylene, polyethylene, and the like). The bolster elements 430 may be formed individually by any suitable process (e.g., by direct injection expanded foam molding). In other embodiments, the bolster elements 430 may be formed together as a single piece. The bolster elements 430 may be formed separately from the non-viscoelastic foam layer 426 and subsequently positioned within the layer 426 (e.g., within cavities formed or otherwise created in the layer 426), or the bolster elements 430 may be formed simultaneously with the non-viscoelastic foam layer 426 using a co-injection molding process. In the illustrated embodiment of the mattress 410, the bolster elements 430 have a hardness of at least about 200 N. In some embodiments, the bolster elements 430 may have a hardness of at least about 2.5 times the hardness of the viscoelastic foam layer 422 and no greater than about 10 times the hardness of the viscoelastic foam layer 422. In such embodiments, the bolster elements 430 can also have a hardness that is greater than that of the non-viscoelastic foam layer 426, such as a hardness of at least 1.1 times that of the non-viscoelastic foam layer 426, or (in other embodiments) a hardness of at least 1.5 times that of the non-viscoelastic foam layer 426, or (in still other embodiments) a hardness that is at least twice that of the non-viscoelastic foam layer 426.

Under an applied force (e.g., in response to a user's weight or exertion), the viscoelastic foam layer 422 may be deformed or compressed further into regions 436 of the mattress 410 corresponding with the troughs 434 than regions 432 of the mattress 410 surrounding the troughs 434 as a result of the relatively high hardness of the bolster elements 430 compared to the layers 422, 426. Accordingly, the user is able to feel the locations of the bolster elements 430 by compressing the foam layers 422, 426 into the troughs 434.

The troughs 434 provide the user with locations or regions 436 on the mattress 410 where the user may increase their mobility (i.e., leverage to initiate movement) on the mattress 410. For example, as shown in FIG. 8, when the user desires to move or change position, the user exerts a force F on the mattress 410 having a line of action through one of the troughs 434. A corresponding reaction force R is exerted on the user by the bolster elements 430. The reaction force R may be resolved into at least lateral and vertical force vector components Rx, Ry.

The lateral component Rx of the reaction force R exerted on the user by one or more of the bolster elements 430 allows the user to accelerate a mass (e.g., the user's body) in a lateral direction. This facilitates lateral movement of the user on the mattress 410, and enables the user to roll, turn, or move off the mattress 410 with reduced effort. In some conventional mattresses including viscoelastic foam, the shape-conforming properties of the viscoelastic foam might allow the user to “sink” into the foam and thereby inhibit their lateral movement, causing the user to struggle when rolling, turning, or moving off such a conventional mattress.

FIGS. 9 and 10 illustrate a mattress 510 according to another embodiment of the invention. This embodiment employs much of the same structure and has many of the same properties as the embodiments of the mattresses 110-410 described above in connection with FIGS. 1-8. Accordingly, the following description focuses primarily upon the structure and features that are different than the embodiments described above in connection with FIGS. 1-8. Reference should be made to the description above in connection with FIGS. 1-8 for additional information regarding the structure and features, and possible alternatives to the structure and features of the mattress illustrated in FIGS. 9 and 10 and described below. Structure and features of the embodiment shown in FIGS. 9 and 10 that correspond to structure and features of the embodiment of FIGS. 1-8 are designated hereinafter in the 500 series of reference numbers.

With reference to FIG. 9, the mattress 510 includes a top surface 514, a bottom surface 518, and a thickness t (FIG. 10) between the top surface 514 and the bottom surface 518. The mattress 510 is substantially rectangular in shape and includes a length dimension L and a width dimension W (FIG. 9). In the illustrated embodiment of the mattress 510 as shown in FIGS. 9 and 10, the top surface 514 and the bottom surface 518 are substantially planar.

The mattress 510 includes a first or overlying viscoelastic foam layer 522 and a second or underlying non-viscoelastic foam layer 526. The viscoelastic foam layer 522 provides the body-conforming and low-resilience qualities associated with viscoelastic foam, while the non-viscoelastic foam layer enhances and/or provides some degree of resilience or “bounce” to the mattress 510 typically associated with conventional spring-based mattresses.

Like the mattresses 110, 210, 310, and 410 described above, the mattress 510 includes a plurality of bolster elements 530 positioned beneath a top surface 522 a of the viscoelastic foam layer 522. In the illustrated embodiment, the bolster elements 530 extend along the entire length L of the mattress 510 and are positioned within the non-viscoelastic foam layer 526. More particularly, the bolster elements 530 are disposed between a top surface 526 a and a bottom surface 526 b of the non-viscoelastic foam layer 526 such that the bolster elements 530 are substantially encased by the non-viscoelastic foam layer 526. However, the bolster elements 530 are not limited to being encased by the non-viscoelastic foam layer 526, and may extend through the mattress 510 at any point along the thickness t, between the top surface 526 a of the viscoelastic foam layer 522 and the bottom surface 526 b of the non-viscoelastic foam layer 526. In addition, the bolster elements 530 may be shorter than the length L of the mattress 510.

In the illustrated embodiment of the mattress 510, the bolster elements 530 have a generally quadrangular or diamond-like cross-sectional shape, and each of the plurality of bolster elements 530 is substantially identical. Adjacent bolster elements 530 are connected by connecting portions or thin webs 552 to form a single bolster 556. Accordingly, the bolster elements 530 and the webs 552 are collectively referred to as the bolster 556.

Like the bolster elements 130, 230, 330, and 430 described above, the bolster 556 is formed from a suitable high-resilience polymeric material, such as polystyrene foam. In some embodiments, the bolster 556 may include any expanded polymer (e.g., expanded ethylene vinyl acetate, polypropylene, polyethylene, and the like). The bolster 556 may be formed separately from the non-viscoelastic foam layer 526 and subsequently positioned within the layer 526 (e.g., within a cavity formed or otherwise created in the layer 526), or the bolster 556 may be formed simultaneously with the non-viscoelastic foam layer 526 using a co-injection molding process. In the illustrated embodiment of the mattress 510, the bolster 556 has a hardness of at least about 200 N. In some embodiments, the bolster 556 may have a hardness of at least about 2.5 times the hardness of the viscoelastic foam layer 522 and no greater than about 10 times the hardness of the viscoelastic foam layer 522. In such embodiments, the bolster elements 530 can also have a hardness that is greater than that of the non-viscoelastic foam layer 526, such as a hardness of at least 1.1 times that of the non-viscoelastic foam layer 526, or (in other embodiments) a hardness of at least 1.5 times that of the non-viscoelastic foam layer 526, or (in still other embodiments) a hardness that is at least twice that of the non-viscoelastic foam layer 526.

With reference to FIG. 10, a plurality of troughs 534 is defined between adjacent bolster elements 530 of the bolster 556. Each of the troughs 534 is defined by facing, oblique surfaces 538 of adjacent bolster elements 530, respectively. In the illustrated embodiment of the mattress 510, the troughs 534 extend along the entire length L of the mattress 510 with the bolster 556. Under an applied force (e.g., in response to a user's weight or exertion), the viscoelastic foam layer 522 may be deformed or compressed further into regions 536 of the mattress 510 corresponding with the troughs 534 than regions 532 of the mattress 510 surrounding the troughs 534 as a result of the relatively high hardness of the bolster 556 compared to the layers 522, 526. Accordingly, the user is able to feel the locations of the bolster elements 530 by compressing the foam layers 522, 526 into the troughs 534.

The troughs 534 provide the user with locations or regions 536 on the mattress 510 where the user may increase their mobility (i.e., leverage to initiate movement) on the mattress 510. For example, as shown in FIG. 10, when the user desires to move or change position, the user exerts a force F on the mattress 510 having a line of action through one of the troughs 534. A corresponding reaction force R is exerted on the user by the bolster elements 530. Depending upon the particular line of action of the exertion force F, the reaction force R may have a line of action normal to the surface 538 of the bolster element 530. The reaction force R may be resolved into at least lateral and vertical force vector components Rx, Ry.

The lateral component Rx of the reaction force R exerted on the user by one or more of the bolster elements 530 allows the user to accelerate a mass (e.g., the user's body) in a lateral direction. This facilitates lateral movement of the user on the mattress 510, and enables the user to roll, turn, or move off the mattress 510 with reduced effort. In some conventional mattresses including viscoelastic foam, the shape-conforming properties of the viscoelastic foam might allow the user to “sink” into the foam and thereby inhibit their lateral movement, causing the user to struggle when rolling, turning, or moving off such a conventional mattress.

FIGS. 11 and 12 illustrate a mattress 610 according to another embodiment of the invention. This embodiment employs much of the same structure and has many of the same properties as the embodiments of the mattresses 110-510 described above in connection with FIGS. 1-10. Accordingly, the following description focuses primarily upon the structure and features that are different than the embodiments described above in connection with FIGS. 1-10. Reference should be made to the description above in connection with FIGS. 1-10 for additional information regarding the structure and features, and possible alternatives to the structure and features of the mattress illustrated in FIGS. 11 and 12 and described below. Structure and features of the embodiment shown in FIGS. 11 and 12 that correspond to structure and features of the embodiments of FIGS. 1-10 are designated hereinafter in the 600 series of reference numbers.

With reference to FIG. 11, the mattress 610 includes a top surface 614, a bottom surface 618, and a thickness t (FIG. 12) between the top surface 614 and the bottom surface 618. The mattress 610 is substantially rectangular in shape and includes a length dimension L and a width dimension W (FIG. 11). In the illustrated embodiment of the mattress 610 as shown in FIGS. 10 and 11, the top surface 614 and the bottom surface 618 are substantially planar.

The mattress 610 includes a first or overlying viscoelastic foam layer 622 and a second or underlying non-viscoelastic foam layer 626. The viscoelastic foam layer 622 provides the body-conforming and law-resilience qualities associated with viscoelastic foam, while the non-viscoelastic foam layer enhances and/or provides some degree of resilience or “bounce” to the mattress 610 typically associated with conventional spring-based mattresses.

Like the mattresses 110, 210, 310, 410, and 510 described above, the mattress 610 includes a plurality of bolster elements 630 positioned beneath a top surface 622 a of the viscoelastic foam layer 622. In the illustrated embodiment, the bolster elements 630 extend along the entire length L of the mattress 610 and are positioned within the non-viscoelastic foam layer 626. More particularly, the bolster elements 630 are disposed between a top surface 626 a and a bottom surface 626 b of the non-viscoelastic foam layer 626 such that the bolster elements 630 are substantially encased by the non-viscoelastic foam layer 626. However, the bolster elements 630 are not limited to being encased by the non-viscoelastic foam layer 626, and may extend through the mattress 610 at any point along the thickness t, between the top surface 626 a of the viscoelastic foam layer 622 and the bottom surface 626 b of the non-viscoelastic foam layer 626. In addition, the bolster elements 630 may be shorter than the length L of the mattress 610.

In the illustrated embodiment of the mattress 610, the bolster elements 630 have a generally hexagonal shape, and each of the plurality of bolster elements 630 is substantially identical. Adjacent bolster elements 630 are connected by connecting portions or thin webs 652 to form a single bolster 656. Accordingly, the bolster elements 630 and the webs 652 are collectively referred to as the bolster 656.

Like the bolster 556 described above, the bolster 656 is formed from a suitable high-resilience polymeric material, such as polystyrene foam. In some embodiments, the bolster 656 may include any expanded polymer (e.g., expanded ethylene vinyl acetate, polypropylene, polyethylene, and the like). The holster 656 may be formed separately from the non-viscoelastic foam layer 626 and subsequently positioned within the layer 626 (e.g., within a cavity formed or otherwise created in the layer 626), or the bolster 656 may be formed simultaneously with the non-viscoelastic foam layer 626 using a co-injection molding process. In the illustrated embodiment of the mattress 610, the bolster 656 has a hardness of at least about 200 N. In some embodiments, the bolster 656 may have a hardness of at least about 2.5 times the hardness of the viscoelastic foam layer 622 and no greater than about 10 times the hardness of the viscoelastic foam layer 622. In such embodiments, the bolster elements 630 can also have a hardness that is greater than that of the non-viscoelastic foam layer 626, such as a hardness of at least 1.1 times that of the non-viscoelastic foam layer 626, or (in other embodiments) a hardness of at least 1.5 times that of the non-viscoelastic foam layer 626, or (in still other embodiments) a hardness that is at least twice that of the non-viscoelastic foam layer 626.

With reference to FIG. 12, a plurality of troughs 634 is defined between adjacent bolster elements 630 of the bolster 656. Each of the troughs 634 is defined by facing, oblique surfaces 638 of adjacent bolster elements 630, respectively. In the illustrated embodiment of the mattress 610, the troughs 634 extend along the entire length L of the mattress 610 with the bolster 656. Under an applied force (e.g., in response to a user's weight or exertion), the viscoelastic foam layer 622 may be deformed or compressed further into regions 636 of the mattress 610 corresponding with the troughs 634 than regions 632 of the mattress 610 surrounding the troughs 634 as a result of the relatively high hardness of the bolster 656 compared to the layers 622, 626. Accordingly, the user is able to feel the locations of the bolster elements 630 by compressing the foam layers 622, 626 into the troughs 634.

The troughs 634 provide the user with locations or regions 636 on the mattress 610 where the user may increase their mobility (i.e., leverage to initiate movement) on the mattress 610. For example, as shown in FIG. 12, when the user desires to move or change position, the user exerts a force F on the mattress 610 having a line of action through one of the troughs 634. A corresponding reaction force R is exerted on the user by the bolster elements 630. Depending upon the particular line of action of the exertion force F, the reaction force R may have a line of action normal to the surface 638 of the bolster element 630. The reaction force R may be resolved into at least lateral and vertical force vector components Rx, Ry.

The lateral component Rx of the reaction force R exerted on the user by one or more of the bolster elements 630 allows the user to accelerate a mass (e.g., the user's body) in a lateral direction. This facilitates lateral movement of the user on the mattress 610, and enables the user to roll, turn, or move off the mattress 610 with reduced effort. In some conventional mattresses including viscoelastic foam, the shape-conforming properties of the viscoelastic foam might allow the user to “sink” into the foam and thereby inhibit their lateral movement, causing the user to struggle when rolling, turning, or moving such a conventional mattress.

Although not subscribing to any theory or scientific principle by which the performance of the mattresses 110, 210, 310, 410, 510, and 610 described above is defined, it is believed that the use of the bolster elements 130, 230, 330, 430, 530, 630 within a foam mattress (the properties of which are described above) results in a mattress having the low-resilience, soft feel, and body-conforming properties or qualities of viscoelastic foam without impairing a user's mobility on the mattress. For example, the user is better able to roll, turn, prop, or otherwise change position by applying force to the relatively firm bolster elements 130, 230, 330, 430, 530, 630. Accordingly, in some embodiments, the use of such bolster elements 130, 230, 330, 430, 530, 630 can limit or attenuate the impaired mobility that is normally experienced with many conventional viscoelastic foam mattresses. In addition, as evidenced by the various embodiments illustrated in FIGS. 1-12, the shape, size, quantity, position, orientation, and construction of the bolster elements 130, 230, 330, 430, 530, 630 can therefore be selected to essentially “tune” the mattress to have any desired feel (i.e., the feel by the user of the body conforming and pressure-distributing properties of viscoelastic foam), while still maintaining the benefits of enhanced mobility as described above.

The embodiments described above and illustrated in the figures are presented by way of example only and are not intended as a limitation upon the concepts and principles of the present invention. As such, it will be appreciated by one having ordinary skill in the art that various changes in the elements and their configuration and arrangement are possible without departing from the spirit and scope of the present invention. By way of example only, the various mattress embodiments described and/or illustrated herein are presented as having a particular construction or arrangement of bolster elements. Although unique and desirable properties result from such structures, mattresses according to other embodiments of the present invention have other constructions or arrangements of bolster elements than those described and illustrated herein.

It should be appreciated that the features of the mattresses 110, 210, 310, 410, 510, and 610 described above and illustrated in FIGS. 1-12 are applicable to any other type of body support having any size and shape. By way of example only, any of the features described above are equally applicable to mattress toppers, overlays, futons, sleeper sofas, or any other element used to support or cushion any part or all of a human or animal body. Accordingly, as used herein, the term “mattress” is intended to refer to any and all of such elements (in addition to mattresses).

Various features of the invention are set forth in the following claims. 

What is claimed is:
 1. A mattress comprising: a first layer of viscoelastic foam having an upper surface; a layer of non-viscoelastic foam supporting the first layer; and a plurality of static bolster elements positioned beneath the upper surface and clustered together to define a plurality of troughs between adjacent bolster elements, wherein the first layer of viscoelastic foam is further compressible in regions of the mattress corresponding with the troughs than surrounding regions corresponding with the bolster elements, and wherein each of the bolster elements is capable of exerting a reaction force having a lateral component on an individual pushing against the bolster element with a line of action through, one of the troughs.
 2. The mattress of claim 1, wherein the bolster elements are elongated in a length dimension of the mattress.
 3. The mattress of claim 2, wherein the troughs are elongated in the length dimension of the mattress.
 4. The mattress of claim 2, wherein the bolster elements extend substantially the entire length of the mattress.
 5. The mattress of claim 1, wherein the bolster elements and the troughs are parallel.
 6. The mattress of claim 1, wherein the bolster elements are elongated in a thickness dimension of the mattress.
 7. The mattress of claim 1, wherein the bolster elements include a greater hardness than the first layer of viscoelastic foam.
 8. The mattress of claim 7, wherein the first layer of viscoelastic foam includes a hardness of at least about 20 N and no greater than about 80 N.
 9. The mattress of claim 1, wherein the layer of non-viscoelastic foam is one of a latex foam and a high-resilience polyurethane foam.
 10. The mattress of claim 9, wherein, the latex foam includes a hardness of at least about 30 N and no greater than about 130 N, and wherein the high-resilience polyurethane foam includes a hardness of at least about 80 N and no greater than about 200 N.
 11. The mattress of claim 9, wherein the latex foam includes a density of no less than about 40 kg/m³ and no greater than about 100 kg/m³, and wherein the high-resilience polyurethane foam includes a density of no less than about 10 kg/m³ and no greater than about 80 kg/m³.
 12. The mattress of claim 1, wherein the first layer of viscoelastic foam includes a density of no less than about 30 kg/m³ and no greater than about 150 kg/m³.
 13. The mattress of claim 1, wherein the bolster elements include a circular cross-sectional shape.
 14. The mattress of claim 13, wherein the bolster elements are cylindrical and arranged in a side-by-side manner.
 15. The mattress of claim 14, wherein each of the troughs is defined by convex surfaces of adjacent cylindrical bolster elements, respectively.
 16. The mattress of claim 15, wherein a line of action of the reaction force exerted by one of the bolster elements in response to an individual pushing against the bolster element is oriented substantially normal to the convex surface of the bolster element.
 17. The mattress of claim 1, wherein the bolster elements include a non-circular cross-sectional shape.
 18. The mattress of claim 17, wherein the bolster elements include a hexagonal cross-sectional shape, and wherein the bolster elements are arranged in a side-by-side manner.
 19. The mattress of claim 18, wherein each of the troughs is defined by flat surfaces of adjacent hexagonal bolster elements, respectively.
 20. The mattress of claim 19, wherein a line of action of the reaction force exerted by one of the bolster elements in response to an individual pushing against the bolster element is oriented substantially normal to the flat surface of the bolster element.
 21. The mattress of claim 1, wherein the bolster elements are arranged in a first row positioned beneath the upper surface and a second row positioned beneath the first row.
 22. The mattress of claim 21, wherein the bolster elements in the first and second rows are also aligned in an array of columns.
 23. The mattress of claim 1, wherein adjacent bolster elements are contiguous.
 24. The mattress of claim 1, wherein adjacent bolster elements are integrally formed as a single piece.
 25. The mattress of claim 1, wherein the bolster elements include a greater hardness than either of the first layer of viscoelastic foam or the non-viscoelastic foam layer of non-viscoelastic foam.
 26. The mattress of claim 25, wherein the bolster elements include a hardness of at least about 200 N.
 27. The mattress of claim 1, wherein the bolster elements are made of, a polymeric material.
 28. The mattress of claim 1, wherein the bolster elements are made of polystyrene foam.
 29. The mattress of claim 1, wherein the bolster elements are embedded in the layer of non-viscoelastic foam.
 30. The mattress of claim 1, wherein the bolster elements are positioned between the first layer of viscoelastic foam and the non-viscoelastic foam layer of non-viscoelastic foam.
 31. A mattress comprising: a first layer of viscoelastic foam having an upper surface; a layer of non-viscoelastic foam supporting the first layer; and a plurality of static bolster elements positioned beneath the upper surface and clustered together to define a plurality of troughs between adjacent bolster elements, wherein the bolster elements and the troughs extend in a direction parallel to a length of the mattress, and wherein the bolster elements include a hardness that is at least about 2.5 times a hardness of the first layer of viscoelastic foam.
 32. The mattress of claim 31, wherein the first layer of viscoelastic foam includes a hardness of at least about 20 N and no greater than about 80 N.
 33. The mattress of claim 32, wherein the bolster elements include a hardness of at least about 200 N.
 34. The mattress of claim 31, wherein the hardness of the bolster elements is between about 2.5 times and about 10 times the hardness of the first layer of viscoelastic foam.
 35. The mattress of claim 31, wherein the first layer of viscoelastic foam is further compressible in regions of the mattress corresponding with the troughs than surrounding regions corresponding with the bolster elements, and wherein each of the bolster elements is capable of exerting a reaction force having a lateral component on an individual pushing against the bolster element with a line of action through one of the troughs. 